Sabtu, 01 Agustus 2009

ACID BASE TITRATION QUIZ

1. 50 mL of HCl(aq) is titrated with 0,10 M NaOH(aq). If the volume of NaOH needed is 60 mL, the [HCl] is ….

a. 0,08 M b. 0,01 M c. 0,12 M d. 0,15 M e. 0,20 M

2. The pH of the equivalent point is ….

a. 2 b. 5 c. < 7 d. 7 e. > 7

3. When the volume of NaOH which added to HCl(aq) is 25 mL, the pH of solution is ….

a. 1 – log 3 b. 1 + log 3 c. > 1 d. < 7 e. 7 + log 3

4. The pH after the addition of 50 mL of NaOH(aq) is ….

a. > 2 b. 2 c. 5 d. 7 e. < 7

5. The pH after the addition of 70 mL of NaOH(aq) is ….

a. 3 – 3log2 b. 3 + 3log2 c. 7 d. 11 – 3log2 e. 11 + 3log2

6. Which indicator would probably not work for detecting the endpoint, when strong acid is titrated with a strong base?

a. bromocresol purple, with a color change in the range pH = 5.2 to b. thymol blue, with a color change in the range pH = 8.0 to 9.6 c. bromophenol blue, with a color change in the range pH = 3.0 to 4. d. bromothymol blue, with a color change in the range pH = 6.0 to 7.6

7. If the above titration uses other indicators, which indicator would be worked?

a. MO, with a color change in the range pH = 3,1 to 4,4 b. MR, with a color change in the range pH = 4,2 to 6,2 c. PP, with a color change in the range pH = 8.3 to 10.0 d. MO or PP

15. How many grams of solid sodium hydroxide may be neutralized by 150 mL of 0.150 HCl?

a. 90g b. 1.11g c. 9g d. 11.2g e. 0.9g

16. Calculate the concentration of a 25.0 mL sample of mono-protic acid if it took 31.6mL of 0.110 M NaOH to neutralize it completely.

a. 0.139 b. 0.159 c. 0.087 d. 0.87 e. 11.5

17. The stoichiometric point in an acid-base titration ….

a. will always have a pH of 7.00 b. will have a pH of 7.00 when it involves a strong acid and strong base c. will have a pH of 7.00 when a weak acid and a weak base are used d. will have a pH above 7.00 when a weak base and a strong acid are used e. will have a pH below 7.00 when a weak acid and a strong base are used

18. A 25.00 mL sample of 0.100 M HCl is titrated with 0.100 M NaOH. What is the pH of the solution at the points where 24.5 and 25.5 mL of NaOH have been added.

19. What is the pH of 100.0 mL of 0.100 M HCl after 20.0 mL of 0.100 M NaOH have been added?

a. 0.98 b. 1.17 c. 1.86 d. 2.02 e. 2.42

20. What is the pH of 100.0 mL of 0.100 M HCl after 100.0 mL of 0.100 M NaOH have been added?

a.0.00 b.1.00 c.6.86 d.7.00 e.7.25

21.What is the pH of 100.0 mL of 0.100 M HCl after 150.0 mL of 0.100 M NaOH have been added?

a. 1.70 b. 5.89 c. 8.98 d. 10.78 e. 12.30

22.The pH of a titration of 0.10M HCl by 0.150M NaOH at equivalence point is ....

a. 6.85 b. 7.00 c. 7.15 d. 7.36 e. 8.20

23. What is the pH of a solution in which 25.0 mL of 0.010 M Sr(OH)2 are added to 20.0 mL of 0.020 M H2SO4?

a. 11.82 b. 11.52 c. 2.52 d. 2.48 e. 1.76

24. A 1.20 g sample of fumaric acid is dissolved in 100.0 mL of water and titrated with 0.300 M NaOH to the second equivalence point. The volume of base used is 69.0 mL. What is the molecular mass of fumaric acid which contains two dissociable protons?

a. 84 b. 116 c. 142 d. 58 e. 232

25. A 1.50 g sample of Vitamin C is dissolved in 100.0 mL of water and titrated with 0.250 M NaOH to the methyl orange equivalence point. The volume of the base used is 34.1 mL. What is the molecular mass of Vitamin C assuming one dissociable proton per molecule?

a. 139 b. 176 c. 146 d. 164 e. 152

26. 0.550 g sample of butyric acid is dissolved in 100.0 mL of water and titrated with 0.100 M NaOH to the phenolphthalein equivalence point. The volume of the base used is 62.4 mL. What is the molecular mass of butyric acid assuming one dissociable proton per molecule?

a. 140 b. 88 c. 122 d. 160 e. 46

27. A 25.00 mL sample of 0.100 M CH3CO2H is titrated with 0.100 M NaOH. What is the pH of the solution at the points where 24.0 and 24.5 mL of NaOH have been added. (Ka = 1.8x10-5)

a. 5.32, 6.13 b. 5.61, 6.44 c. 5.61, 6.13 d. 6.13, 7.00 e. 6.13, 6.43

28. A 25.00 mL sample of 0.100 M CH3CO2H is titrated with 0.100 M NaOH. What is the pH of the solution at the points where 24.0 and 26.5 mL of NaOH have been added. (Ka=1.8 x 10-5)